Polymeric material, containing a latent acid

ABSTRACT

Polymeric material, containing a latent acid which can be converted to an acid by irradiation by a laser and optionally further ingredients.

[0001] The present application relates to polymeric material containinga latent acid, i.e. a compound which is not an acid but which can beconverted to an acid by the influence of irradiation.

[0002] For specific technical applications, compositions are requestedcontaining compounds which are capable of reacting with acids, however,such a reaction should be suppressed until a predetermined moment. It iscommon practice in such cases to separate the compounds and the acids bysuitable measures, e.g. by encapsulating them into coverings anddestroying these coverings when reaction is desired. This method is,however, not practicable in many cases.

[0003] The present application describes an elegant solution for thatproblem by using not acids but latent acids. Thus the compounds capableof reacting with acids can be intimately mixed with the latent acidswithout reaction. No covering material is required. At the desiredmoment reaction can easily be achieved by irradiating the mixture in asuitable manner to convert the latent acid into the acid, which thenreacts with the compound.

[0004] The present application concerns polymeric material, containing alatent acid, which can be converted to an acid by irradiation andoptionally further ingredients.

[0005] As latent acids compounds are suitable which are not acids per seand contain a proton, which can be split off by irradiation.

[0006] Preferred latent acids are compounds of formula

[0007] wherein

[0008] the ring A can contain one or more hetero atoms and/or cancontain an anelated ring,

[0009] R₁ is hydrogen, alkyl, preferably C₁-C₂₀-alkyl, alkenyl,preferably C₂-C₂₀-alkenyl, aryl, preferably phenyl or phenyl which issubstituted one to three times with C₁-C₄alkyl, or C₁-C₄alkoxy,

[0010] R₂, R₃, R₄ and R₅ independently of each other are hydrogen or afunctional substituent, and R stands for C₁-C₆alkyl, -Z₁-Q₁, or -Z₂-Q₂,

[0011] wherein Z₁ is a single bond, S, NH or O, and Q₁ is a heterocyclicring system having from 5 to 9 ring atoms selected from C, S, O and N,with at least 2, preferably at least 3, more preferably at least 4carbon atoms in the ring system, preferably Q₁ stands for morpholine,pyridine, which may be substituted one to three times with C₁-C₄alkyl orhydroxy, mercaptobenzoxazole, mercaptobenzthiazole,

[0012] and wherein Z₂ stands for C₁-C₄alkylene, which can be substitutedby C₁-C₄alkyl or Q₃, wherein Q₃ stands for phenyl which can besubstituted one to three times with C₁-C₄alkyl, hydroxy, C₅-C₈cycloalkyl and/or a heterocyclic ring system having from 5 to 9 ringatoms selected from C, S, O and N, with at least 2, preferably at least3, more preferably at least 4 carbon atoms in the ring system, and Q₂stands for phenyl which can be substituted one to three times withC₁-C₄alkyl, hydroxy, C₅-C₈cycloalkyl and/or a heterocyclic ring systemhaving from 5 to 9 ring atoms selected from C, S, O and N, with at least2, preferably at least 3, more preferably at least 4 carbon atoms in thering system, with the proviso that the hydrogen atom at the C-atom inα-position to R can be split off by irradiation.

[0013] Preferably, Z₂ stands for —CH₂—, —CH₂—CH₂—, —CH₂—CHMe-,—CH₂—CHQ₃-, in which Q₃ stands for 4-hydroxy-3-1-propyl-6-methylphenyl,4-hydroxy-3-tert.-butyl-6-methylphenyl, or4-hydroxy-3-cyclohexyl-6-methylphenyl and Q₂ stands for phenyl or4-hydroxy-3-1-propyl-6-methylphenyl,4-hydroxy-3-tert.-butyl-6-methylphenyl, or4-hydroxy-3-cyclohexyl-6-methylphenyl.

[0014] Suitable rings A are e.g. phenyl, naphthyl, pyridyl andquinolinyl, phenyl and pyridyl are especially preferred.

[0015] R₁ is preferably hydrogen, or methyl.

[0016] Functional substituents R₂, R₃, R₄ and R₅ are e.g. C₁-C₂₀-alkyl,preferably C₁-C₈-alkyl, particularly preferred C₁-C₆-alkyl, especiallypreferred C₁-C₄-alkyl, C₅-C₈-cycloalkyl, C₂-C₂₀-alkenyl, preferredC₂-C₆-alkenyl, C₁-C₆-alkoxy, hydroxy, halogen, nitro, cyano, —SO₂R′,wherein R′ is hydrogen, alkyl or a metallic cation such as a alkalimetal, e.g. sodium or potassium, or earth alkali metal cation, e.g.calcium, or phenyl, which may be substituted one to three times withhydroxy and/or Z₂₁-R₇, wherein Z₂₁ stands for C₁-C₄alkylene, which canbe substituted by C₁-C₄alkyl, and R₇ stands for hydrogen, C₁-C₄alkyl orphenyl, which may be substituted one to three times with hydroxy,C₁-C₄alkyl and/or Z₂₂-R₈, wherein Z₂₂ stands for for C₁-C₄alkylene,which can be substituted by C₁-C₄alkyl, and R₈ stands for a heterocyclicring system having from 5 to 9 ring atoms selected from C, S, O and N,with at least 2, preferably at least 3, more preferably at least 4carbon atoms in the ring system, preferably R₈ stands for morpholine. Ina preferred embodiment of this invention R₂, R₃, R₄ and R₅ arepreferably independently of each other hydrogen, C₁-C₂₀-alkyl orC₂-C₂₀-alkenyl or substituted phenyl wherein hydroxy and Z₂₁-R₇ beingthe substituents. Especially preferred compounds of formula (1) arethose wherein R₂ and R₃ are independently of each other C₁-C₈-alkyl andR₄ and R₅ are each hydrogen.

[0017] Halogen means fluoro, chloro, bromo, or iodo, preferably chloro.

[0018] Heterocyclic residue or heterocyclic ring system having at least2, preferably at least 3, more preferably at least 4 carbon atoms meanse.g. an optionally substituted monocyclic or bicycliclic heterocyclicresidue such as pyrrolidino, piperidino, morpholino, benzthiazole,1,2,4-triazole, imidazole, pyrazole, tetrazole, thiazolin-2-thione,imidazolin-2-thione, N-methylimidazolon-2-thione and5-(3-phenyl-1,3,4-thia-diazol-2(3H)-thione), 2-pyridine, 4-pyridine,3-pyridazine, 2-pyrimidine, 2-thiazole, 2-thioazoline,3-(1,2,4-triazole) and 5-(2-mercapto-1,3,4-thiadiazole), naphthyridine,purine and pteridine residues, benzimiazole, benzotriazole,benzoxazolin-2-thione, 2-benzoxazole, mercaptobenzoxazol,mercaptobenzthiazol and quinolinyl.

[0019] It is furthermore preferred that at least one of R₂ and R₃ is ino-position to the OH-group.

[0020] The organic residue R can be of any kind with the proviso thatthe hydrogen atom at the Catom in α-position to R can be split off byirradiation. Preferably R is a heterocyclic residue which is bond via anitrogen, oxygen or sulfur atom or is a C₁-C₆-alkyl which isunsubstituted or substituted, e.g. by hydroxy, C₁-C₆-alkoxy orunsubstituted or substituted aryl, especially phenyl. Suitablesubstituents for aryl are preferably the above-mentioned substituents R₂through R₅.

[0021] Most preferably R is a radical of mercaptobenzoxazol ormercaptobenzthiazol or C₁-C₄-alkyl which is unsubstituted or substitutedby unsubstituted phenyl or phenyl carrying 1 to 4 substituents selectedfrom the group consisting of C₁-C₆-alkyl, C₁-C₄-alkoxy and hydroxy.

[0022] In preferred compounds of formula (1) the residue —CHRR₁ issituated in o- or p-, especially in p-position to the OH-group.

[0023] C₁-C₂₀-alkyl means e.g. methyl, ethyl, n-, i-propyl, n-, sec.-,iso-, tert.-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl,n-decyl, n-undecyl, n-dodecyl, n-tridecyl, n-tetradecyl, n-pentadecyl,n-hexadecyl, n-heptadecyl, n-octadecyl, n-nonadecyl, n-eicosyl,preferably C₁-C₈-alkyl such as methyl, ethyl, n-, i-propyl, n-, sec.-,iso-, tert.-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, particularlypreferred C₁-C₆-alkyl such as methyl, ethyl, n-, i-propyl, n-, sec.-,iso-, tert.-butyl, n-pentyl, n-hexyl, especially preferred C₁-C₄-alkylsuch as methyl, ethyl, n-, i-propyl, n-, sec.-, iso-, tert.-butyl.

[0024] C₅-C₈-cycloalkyl stands for cyclopentyl, cyclohexyl, cycloheptyl,or cyclooctyl, preferably cyclohexyl.

[0025] C₂-C₂₀-alkenyl stands for e.g. ethenyl, n-, i-propenyl, n-,sec.-, iso-, tert.-butenyl, n-pentenyl, n-hexenyl, n-heptenyl,n-octenyl, n-nonenyl, n-decenyl, n-undecenyl, n-dodecenyl, n-tridecenyl,n-tetradecenyl, n-pentadecenyl, n-hexadecenyl, n-heptadecenyl,n-octadecenyl, n-nonadecenyl, n-eicosenyl, preferably C₂-C₆-alkyl suchas ethenyl, n-, i-propenyl, n-, sec.-, iso-, tert.-butenyl, n-pentenyl,n-hexenyl.

[0026] C₁-C₆-alkoxy stands for e.g. methoxy, ethoxy, n-, i-propoxy, n-,sec.-, iso-, tert.-butoxy, n-pentoxy, n-hexoxy.

[0027] Preferred polymeric material according to the present inventioncontains a latent acid of formula (1) wherein

[0028] the ring A is phenyl or pyridyl,

[0029] R₁ is hydrogen,

[0030] R₂ and R₃ are independently of each other C₁-C₄-alkyl,

[0031] R₄ and R₅ are each hydrogen and

[0032] R is a heterocyclic residue, which is bond to the CHR₁-group viaa nitrogen, oxygen or sulfur atom or is a C₁-C₆-alkyl, which isunsubstituted or substituted.

[0033] Especially preferred compounds of formula (1) are the followingcompounds:

[0034] The compounds of formula (1) are known or can be made in a mannerknown per se, e.g. compound (2) according to GB 2,120,243 and compounds(5) and (6) as described in EP-A-330 613.

[0035] The compounds of the above formulae (7) and (8) are new. Thesecompounds also form part of the subject matter of the present invention.They can be obtained in a conventional manner by reaction ofmercaptobenzothiazole with a 2,5-dialkylphenol and paraformaldehyde.

[0036] Polymeric material useable for the present invention ispreferably synthetic organic polymeric material, especially materialcommonly used for electronic applications.

[0037] In particular the following polymers are preferred:

[0038] 1. Polymers of monoolefins and diolefins, for examplepolypropylene, polyisobutylene, polybut-1-ene, poly-4-methylpent-1-ene,polyvinylcyclohexane, polyisoprene or polybutadiene, as well as polymersof cycloolefins, for instance of cyclopentene or norbornene,polyethylene (which optionally can be crosslinked), for example highdensity polyethylene (HDPE), high density and high molecular weightpolyethylene (HDPE-HMW), high density and ultrahigh molecular weightpolyethylene (HDPE-UHMW), medium density polyethylene (MDPE), lowdensity polyethylene (LDPE), linear low density polyethylene (LLDPE),(VLDPE) and (ULDPE).

[0039] Polyolefins, i.e. the polymers of monoolefins exemplified in thepreceding paragraph, preferably polyethylene and polypropylene, can beprepared by different, and especially by the following, methods:

[0040] a) radical polymerisation (normally under high pressure and atelevated temperature).

[0041] b) catalytic polymerisation using a catalyst that normallycontains one or more than one metal of groups IVb, Vb, VIb or VIII ofthe Periodic Table. These metals usually have one or more than oneligand, typically oxides, halides, alcoholates, esters, ethers, amines,alkyls, alkenyls and/or aryls that may be either π- or σ-coordinated.These metal complexes may be in the free form or fixed on substrates,typically on activated magnesium chloride, titanium(III) chloride,alumina or silicon oxide. These catalysts may be soluble or insoluble inthe polymerisation medium. The catalysts can be used by themselves inthe polymerisation or further activators may be used, typically metalalkyls, metal hydrides, metal alkyl halides, metal alkyl oxides or metalalkyloxanes, said metals being elements of groups Ia, IIa and/or IIIa ofthe Periodic

[0042] Table. The activators may be modified conveniently with furtherester, ether, amine or silyl ether groups. These catalyst systems areusually termed Phillips, Standard Oil Indiana, Ziegler (-Natta), TNZ(DuPont), metallocene or single site catalysts (SSC).

[0043] 2. Mixtures of the polymers mentioned under 1), for examplemixtures of polypropylene with polyisobutylene, polypropylene withpolyethylene (for example PP/HDPE, PP/LDPE) and mixtures of differenttypes of polyethylene (for example LDPE/HDPE).

[0044] 3. Copolymers of monoolefins and diolefins with each other orwith other vinyl monomers, for example ethylene/propylene copolymers,linear low density polyethylene (LLDPE) and mixtures thereof with lowdensity polyethylene (LDPE), propylene/but-1-ene copolymers,propylene/isobutylene copolymers, ethylene/but-1-ene copolymers,ethylene/hexene copoIlymers, ethylene/methylpentene copolymers,ethylene/heptene copolymers, ethylene/octene copolymers,ethylene/vinylcyclohexane copolymers, ethylene/cycloolefin copolymers(e.g. ethylene/norbornene like COC), ethylene/1-olefins copolymers,where the 1-olefin is generated in-situ; propylene/butadiene copolymers,isobutylene/isoprene copolymers, ethylene/vinylcyclohexene copolymers,ethylene/alkyl acrylate copolymers, ethylene/alkyl methacrylatecopolymers, ethylene/vinyl acetate copolymers or ethylene/acrylic acidcopolymers and their salts (ionomers) as well as terpolymers of ethylenewith propylene and a diene such as hexadiene, dicyclopentadiene orethylidene-norbornene; and mixtures of such copolymers with one anotherand with polymers mentioned in 1) above, for examplepolypropylene/ethylene-propylene copolymers, LDPE/ethylene-vinyl acetatecopolymers (EVA), LDPE/ethylene-acrylic acid copolymers (EM), LLDPE/EVA,LLDPE/EAA and alternating or random polyalkylene/carbon monoxidecopolymers and mixtures thereof with other polymers, for examplepolyamides.

[0045] 4. Hydrocarbon resins (for example C₅-C₉) including hydrogenatedmodifications thereof (e.g. tackifiers) and mixtures of polyalkylenesand starch.

[0046] Homopolymers and copolymers from 1.)-4.) may have anystereostructure including syndiotactic, isotactic, hemi-isotactic oratactic; where atactic polymers are preferred. Stereoblock polymers arealso included.

[0047] 5. Polystyrene, poly(p-methylstyrene), poly(α-methylstyrene).

[0048] 6. Aromatic homopolymers and copolymers derived from vinylaromatic monomers including styrene, α-methylstyrene, all isomers ofvinyl toluene, especially p-vinyltoluene, all isomers of ethyl styrene,propyl styrene, vinyl biphenyl, vinyl naphthalene, and vinyl anthracene,and mixtures thereof. Homopolymers and copolymers may have anystereostructure including syndiotactic, isotactic, hemi-isotactic oratactic; where atactic polymers are preferred. Stereoblock polymers arealso included.

[0049] 6a. Copolymers including aforementioned vinyl aromatic monomersand comonomers selected from ethylene, propylene, dienes, nitriles,acids, maleic anhydrides, maleimides, vinyl acetate and vinyl chlorideor acrylic derivatives and mixtures thereof, for examplestyrene/butadiene, styrene/acrylonitrile, styrene/ethylene(interpolymers), styrene/alkyl methacrylate, styrene/butadiene/alkylacrylate, styrene/butadiene/alkyl methacrylate, styrene/maleicanhydride, styrene/acrylonitrile/methyl acrylate; mixtures of highimpact strength of styrene copolymers and another polymer, for example apolyacrylate, a diene polymer or an ethylene/propylene/diene terpolymer;and block copolymers of styrene such as styrene/butadiene/styrene,styrene/isoprene/styrene, styrene/ethylene/butylene/styrene orstyrene/ethylene/propylene/styrene.

[0050] 6b. Hydrogenated aromatic polymers derived from hydrogenation ofpolymers mentioned under 6.), especially includingpolycyclohexylethylene (PCHE) prepared by hydrogenating atacticpolystyrene, often referred to as polyvinylcyclohexane (PVCH).

[0051] 6c. Hydrogenated aromatic polymers derived from hydrogenation ofpolymers mentioned under 6a.).

[0052] Homopolymers and copolymers may have any stereostructureincluding syndiotactic, isotactic, hemi-isotactic or atactic; whereatactic polymers are preferred. Stereoblock polymers are also included.

[0053] 7. Graft copolymers of vinyl aromatic monomers such as styrene orα-methylstyrene, for example styrene on polybutadiene, styrene onpolybutadiene-styrene or polybutadiene-acrylonitrile copolymers; styreneand acrylonitrile (or methacrylonitrile) on polybutadiene; styrene,acrylonitrile and methyl methacrylate on polybutadiene; styrene andmaleic anhydride on polybutadiene; styrene, acrylonitrile and maleicanhydride or maleimide on polybutadiene; styrene and maleimide onpolybutadiene; styrene and alkyl acrylates or methacrylates onpolybutadiene; styrene and acrylonitrile on ethylene/propylene/dieneterpolymers; styrene and acrylonitrile on polyalkyl acrylates orpolyalkyl methacrylates, styrene and acrylonitrile on acrylate/butadienecopolymers, as well as mixtures thereof with the copolymers listed under6), for example the copolymer mixtures known as ABS, MBS, ASA or AESpolymers.

[0054] 8. Halogen-containing polymers such as polychloroprene,chlorinated rubbers, chlorinated and brominated copolymer ofisobutylene-isoprene (halobutyl rubber), chlorinated or sulfochlorinatedpolyethylene, copolymers of ethylene and chlorinated ethylene,epichlorohydrin homo- and copolymers, especially polymers ofhalogen-containing vinyl compounds, for example polyvinyl chloride,polyvinylidene chloride, polyvinyl fluoride, polyvinylidene fluoride, aswell as copolymers thereof such as vinyl chloride/vinylidene chloride,vinyl chloride/vinyl acetate or vinylidene chloride/vinyl acetatecopolymers.

[0055] 9. Polymers derived from α,β-unsaturated acids and derivativesthereof such as polyacrylates and polymethacrylates; polymethylmethacrylates, polyacrylamides and polyacrylonitriles, impact-modifiedwith butyl acrylate.

[0056] 10. Copolymers of the monomers mentioned under 9) with each otheror with other unsaturated monomers, for example acrylonitrile/butadienecopolymers, acrylonitrile/alkyl acrylate copolymers,acrylonitrile/alkoxyalkyl acrylate or acrylonitrile/vinyl halidecopolymers or acrylonitrile/alkyl methacrylate/butadiene terpolymers.

[0057] 11. Polymers derived from unsaturated alcohols and amines or theacyl derivatives or acetals thereof, for example polyvinyl alcohol,polyvinyl acetate, polyvinyl stearate, polyvinyl benzoate, polyvinylmaleate, polyvinyl butyral, polyallyl phthalate or polyallyl melamine;as well as their copolymers with olefins mentioned in 1) above.

[0058] 12. Homopolymers and copolymers of cyclic ethers such aspolyalkylene glycols, polyethylene oxide, polypropylene oxide orcopolymers thereof with bisglycidyl ethers.

[0059] 13. Polyacetals such as polyoxymethylene and thosepolyoxymethylenes, which contain ethylene oxide as a comonomer;polyacetals modified with thermoplastic polyurethanes, acrylates or MBS.

[0060] 14. Polyphenylene oxides and sulfides, and mixtures ofpolyphenylene oxides with styrene polymers or polyamides.

[0061] 15. Polyurethanes derived from hydroxyl-terminated polyethers,polyesters or polybutadienes on the one hand and aliphatic or aromaticpolyisocyanates on the other, as well as precursors thereof.

[0062] 16. Polyamides and copolyamides derived from diamines anddicarboxylic acids and/or from aminocarboxylic acids or thecorresponding lactams, for example polyamide 4, polyamide 6, polyamide6/6, 6/10, 6/9, 6/12, 4/6, 12/12, polyamide 11, polyamide 12, aromaticpolyamides starting from m-xylene diamine and adipic acid; polyamidesprepared from hexamethylenediamine and isophthalic or/and terephthalicacid and with or without an elastomer as modifier, for examplepoly-2,4,4,-trimethylhexamethylene terephthalamide or poly-m-phenyleneisophthalamide; and also block copolymers of the aforementionedpolyamides with polyolefins, olefin copolymers, ionomers or chemicallybonded or grafted elastomers; or with polyethers, e.g. with polyethyleneglycol, polypropylene glycol or polytetramethylene glycol; as well aspolyamides or copolyamides modified with EPDM or ABS; and polyamidescondensed during processing (RIM polyamide systems).

[0063] 17. Polyureas, polyimides, polyamide-imides, polyetherimids,polyesterimids, polyhydantoins and polybenzimidazoles.

[0064] 18. Polyesters derived from dicarboxylic acids and diols and/orfrom hydroxycarboxylic acids or the corresponding lactones, for examplepolyethylene terephthalate, polybutylene terephthalate,poly-1,4-dimethylolcyclohexane terephthalate, polyalkylene naphthalate(PAN) and polyhydroxybenzoates, as well as block copolyether estersderived from hydroxyl-terminated polyethers; and also polyestersmodified with polycarbonates or MBS.

[0065] 19. Polycarbonates and polyester carbonates.

[0066] 20. Polyketones.

[0067] 21. Polysulfones, polyether sulfones and polyether ketones.

[0068] 22. Crosslinked polymers derived from aldehydes on the one handand phenols, ureas and melamines on the other hand, such asphenovformaldehyde resins, urea/formaldehyde resins andmelamine/formaldehyde resins.

[0069] 23. Drying and non-drying alkyd resins.

[0070] 24. Unsaturated polyester resins derived from copolyesters ofsaturated and unsaturated dicarboxylic acids with polyhydric alcoholsand vinyl compounds as crosslinking agents, and also halogen-containingmodifications thereof of low flammability.

[0071] 25. Crosslinkable acrylic resins derived from substitutedacrylates, for example epoxy acrylates, urethane acrylates or polyesteracrylates.

[0072] 26. Alkyd resins, polyester resins and acrylate resinscrosslinked with melamine resins, urea resins, isocyanates,isocyanurates, polyisocyanates or epoxy resins.

[0073] 27. Crosslinked epoxy resins derived from aliphatic,cycloaliphatic, heterocyclic or aromatic glycidyl compounds, e.g.products of diglycidyl ethers of bisphenol A and bisphenol F, which arecrosslinked with customary hardeners such as anhydrides or amines, withor without α-celerators.

[0074] 28. Natural polymers such as cellulose, rubber, gelatin andchemically modified homologous derivatives thereof, for examplecellulose acetates, cellulose propionates and cellulose butyrates, orthe cellulose ethers such as methyl cellulose; as well as rosins andtheir derivatives.

[0075] 29. Blends of the aforementioned polymers (polyblends), forexample PP/EPDM, Polyamide/EPDM or ABS, PVC/EVA, PVC/ABS, PVC/MBS,PC/ABS, PBTP/ABS, PC/ASA, PC/PBT, PVC/CPE, PVC/acrylates,POM/thermoplastic PUR, PC/thermoplastic PUR, POM/acrylate, POM/MBS,PPO/HIPS, PPO/PA 6.6 and copolymers, PA/HDPE, PA/PP, PA/PPO, PBT/PC/ABSor PBT/PET/PC.

[0076] Especially preferred is organic polymeric material made of SAN(copolymer made of styrene and acrylonitrile), PP (polypropylene), PE(polyethylene), PVC (polyvinylchloride), PET(polyethyleneterephthalate), PET-G (glycole-modified PET), PMMA(polymethylmethacrylate) and related polyacrylics, PS (polystyrene), ASA(copolymer made of acrylonitrile, styrene, acrylate), PA (polyamide),ABS (copolymer made of acrylonitrile, styrene, butadiene), LLDPE (linearLDPE), LDPE (low density polyethylene), HDPE (high density polyethylene)and polycarbonate, most preferably polycarbonate. The polymeric materialcan also be a mixture of two or more different polymers.

[0077] The polymeric material usually contains preferably 0.001 to 10%by weight, most preferably 0.01 to 5% by weight of the latent acid (1).The polymeric material may also contain mixtures of two or more of thelatent acids.

[0078] The polymeric material and the latent acid usually form ahomogenous mixture. For specific applications, however, compositions canbe made in which the latent acid is enriched in a specific part of thepolymeric material, e.g. in the surface areas.

[0079] The methods for incorporating the latent acid into the polymericmaterial are in principle known. It is e.g. possible, to dissolve thecomponents in a solvent and then to remove the solvent by evaporation.Another possibility is to melt polymeric material together with thelatent acid to get a homogeneous mixture or to thoroughly knead amixture of polymeric material and latent acid, or to polymerize thecorresponding monomers in the presence of the latent acid.

[0080] In another embodiment of this invention, the latent acid (1) isgrafted on the polymer material by means known in the art. E.g. thelatent acid (1) is converted into a monomer, i.e. by incorporating afunctional polymerizable group, or a monomer is used which isfunctionalized with a latent acid group. This allows a graftpolymerization on the existing polymeric material or a copolymerizationduring the manufacturing the polymeric material.

[0081] The polymeric material usually may contain further ingredients,e.g. stabilizers, antioxidants, softeners etc. as are commonly used forpolymeric material.

[0082] To convert the latent acid into the corresponding acid, thepolymeric material is irradiated. Irradiation in this applicationespecially means irradiation with UV-light and especially withUV-lasers.

[0083] As a rule, the lasers used are commercially available. Thewavelength of the UV-light preferably is chosen in the range of 285 to400 nm, particularly preferred in the range of 285 to 370 nm. Theduration of irradiation depends on the components and on the type ofUV-source and be easily be determined by simple experiments.

[0084] The inventive polymeric material containing a latent acid can beused in a system for laser decoration if the polymeric materialadditionally contains a colourless colour former which gives a visiblecolour after reaction with an acid.

[0085] The following non-limitative examples illustrate the invention inmore detail. Parts and percentages are by weight, unless otherwisestated.

EXAMPLES Example 1

[0086] To a reaction flask are charged 16.7 g of mercaptobenzothiazole,16.4 g 2-t-butyl-5-methylphenol, 3.0 g paraformaldehyde and 1 mldibutylamine. The mixture is heated to 120° C. and held at thistemperature for 6 hours. After cooling to room temperature 75 ml ethanolare added. Then the mixture is heated to reflux for 2 hours and thencooled to 20° C. and filtered. By trituration of the product with hotmethanol a product with melting point 177.9-183.9° C. is obtained. Theproduct is of the following formula:

[0087] Yield 22.5 g (65.6% theory).

Example 2

[0088] Repeating example 1, but replacing 2-t-butyl-5-methylphenol by15.0 g thymol gives a compound of formula

[0089] Melting point 119.3-123.0. Yield 9.6 g (29.2% theory).

Example 3

[0090] 100 parts of polycarbonate, and 1 part of the latent acidaccording to example 1 and 1 part of the colour former of the formula

[0091] are dissolved in tetrahydrofurane. The solvent is allowed toevaporate overnight.

[0092] A colourless homogeneous polymeric material is obtained.Irradiation with a UV-laser at 355 nm produces blue marks at theirradiated areas.

Examples 4 to 8

[0093] In a similar manner to example 3 the following latent acids areincorporated in polycarbonate: Example Latent Acid Parts latent acidParts Colour Former 4 Compound (2) 1 1 5 Compound (8) 1 1 6 Compound(11) 1 1 7 Compound (12) 1 1 8 Compound (13) 1 1

[0094] In each case irradiation with a laser at 355 nm produced a clearblue mark.

1. Polymeric material, containing a latent acid, which can be convertedto an acid by irradiation by a laser, and optionally furtheringredients.
 2. Polymeric material according to claim 1, wherein thelatent acid is of formula

wherein the ring A can contain one or more hetero atoms and/or cancontain an anelated ring, R₁ is hydrogen, alkyl, alkenyl, aryl, R₂, R₃,R₄ and R₅ independently of each other are hydrogen or a functionalsubstituent, and R stands for C₁-C₆alkyl, -Z₁-Q₁, or -Z₂-Q₂, wherein Z₁is a single bond, S, NH or O, and Q₁ is a heterocyclic ring systemhaving from 5 to 9 ring atoms selected from C, S, O and N, with at least2 carbon atoms in the ring system, which may be substituted one to threetimes with C₁-C₄alkyl or hydroxy, mercaptobenzoxazole,mercaptobenzthiazole, and wherein Z₂ stands for C₁-C₄alkylene, which canbe substituted by C₁-C₄alkyl or Q₃, wherein Q₃ stands for phenyl whichcan be substituted one to three times with C₁-C₄alkyl, hydroxy,C₅-C₈cycloalkyl and/or a heterocyclic ring system having from 5 to 9ring atoms selected from C, S, O and N, with at least 2 carbon atoms inthe ring system, and Q₂ stands for phenyl which can be substituted oneto three times with C₁-C₄alkyl, hydroxy, C₅-C₈cycloalkyl and/or aheterocyclic ring system having from 5 to 9 ring atoms selected from C,S, O and N, with at least 2 carbon atoms in the ring system, with theproviso that the hydrogen atom at the C-atom in α-position to R can besplit off by irradiation.
 3. Polymeric material according to any one ofclaims 1 to 2, wherein the polymeric material contains 0.001 to 10% byweight, most preferably 0.01 to 5% by weight of the latent acid. 4.Polymeric material according to any one of claims 1 to 3, wherein thepolymeric material contains as further ingredient a stabilizer, anantioxidant or a softener.
 5. Process for converting the polymericmaterial containing a latent acid according to any one of claims 1 to 4into polymeric material containing an acid, characterized in that thepolymeric material containing a latent acid is irradiated with UV-light.6. Process according to claim 5, wherein irradiation is performed with aUV-laser using UV-light of 285 to 400 nm.
 7. Polymeric material obtainedby a process according to any one of claims 5 or
 6. 8. Compound offormula


9. Compound of formula